Comorbidities and heart failure: heterogeneity and challenges to fill in the gaps
Authors: Albertino Damasceno, Nuno Lunet
Journal: The Lancet Global Health (2023)

In The Lancet Global Health, Teresa Gerhardt and colleagues1Gerhardt T Gerhardt LMS Ouwerkerk W et al.Multimorbidity in patients with acute heart failure across world regions and country income levels (REPORT-HF): a prospective, multicentre, global cohort study.Lancet Glob Health. 2023; 11: e1874-e1884Google Scholar report on the distribution of multimorbidity and its impact on pharmacological treatment and the prognosis of patients with heart failure worldwide. The study included data from 18 553 patients hospitalised with an episode of decompensated chronic heart failure or new-onset acute heart failure, selected in 358 sites from 44 countries, and followed for up 1 year. Although this study is not the first prospective cohort assessment of a large sample of patients with heart failure recruited worldwide, it adds to previous research on the global epidemiology of heart failure by providing detailed data on the prevalence of multimorbidity and its impact among these patients, overall and for each of seven WHO regions and different country income level. Nevertheless, it is relevant for the interpretation of these findings that the only sub-Saharan African country represented in the study is South Africa. The number of Black patients included in the analysis corresponds to less than 5% of the total sample and almost all were Black Americans; among the participants from the Eastern Mediterranean and Africa region, only 2% were Black. The two most important studies of acute heart failure in Africa, the Heart of Soweto2Sliwa K Wilkinson D Hansen C et al.Spectrum of heart disease and risk factors in a black urban population in South Africa (the Heart of Soweto Study): a cohort study.Lancet. 2008; 371: 915-922Summary Full Text Full Text PDF PubMed Scopus (306) Google Scholar and THESUS studies,3Damasceno A Mayosi BM Sani M et al.The causes, treatment, and outcome of acute heart failure in 1006 Africans from 9 countries.Arch Intern Med. 2012; 172: 1386-1394Crossref PubMed Scopus (341) Google Scholar are already more than 10 years old; and since then, only the G-CHF study4Joseph P Roy A Lonn E et al.Global variations in heart failure etiology, management, and outcomes.JAMA. 2023; 329: 1650-1661Crossref Scopus (11) Google Scholar included a more meaningful sample of African patients, namely from Mozambique, Nigeria, South Africa, Sudan, and Uganda. All these studies showed differences in the clinical presentation and prognosis of patients with heart failure from Africa in relation to patients from the rest of the world. The former present an earlier onset of the disease by almost 10–15 years, completely different causes with hypertension, dilated cardiomyopathy, and rheumatic heart disease as the commonest causes, and a higher risk of death.2Sliwa K Wilkinson D Hansen C et al.Spectrum of heart disease and risk factors in a black urban population in South Africa (the Heart of Soweto Study): a cohort study.Lancet. 2008; 371: 915-922Summary Full Text Full Text PDF PubMed Scopus (306) Google Scholar, 3Damasceno A Mayosi BM Sani M et al.The causes, treatment, and outcome of acute heart failure in 1006 Africans from 9 countries.Arch Intern Med. 2012; 172: 1386-1394Crossref PubMed Scopus (341) Google Scholar, 4Joseph P Roy A Lonn E et al.Global variations in heart failure etiology, management, and outcomes.JAMA. 2023; 329: 1650-1661Crossref Scopus (11) Google Scholar Also important for the interpretation of the differences observed between the populations evaluated in studies with such a broad regional coverage, is the possibility of systematic errors, even when similar methods are used across settings with substantially diverse characteristics, both in terms of clinical presentation and prognosis of the patients as well as regarding the access to health care. For example, patients were classified as having valvular heart disease solely based on the history of valvular disease or a previous valve surgery, despite echocardiography data being available for a large proportion of patients. This approach might have contributed to an underestimation of the frequency of this condition, especially in the countries where rheumatic heart disease is more common,5Dougherty S Okello E Mwangi J Kumar RK Rheumatic heart disease: JACC focus seminar 2/4.J Am Coll Cardiol. 2023; 81: 81-94Crossref PubMed Scopus (6) Google Scholar including Egypt, India, South Africa, or those from Central and South America. Differences in the characteristics of the recruitment sites in relation to their case-mix (eg, public or private, and primary care or reference centres) might have led to the selection of patients that do not necessarily represent the distribution of socioeconomic status and patterns of cause and comorbidities in each country, although no detailed information is available for such a discussion. In conclusion, the study by Gerhardt and colleagues is the first to bring important information about the prevalence of different comorbidities in patients with acute heart failure in different parts of the word. The study shows clearly that comorbidities are more common in high-income than in upper-middle or lower-middle-income countries, that they are associated with worse outcomes, with less frequent use of guideline-directed therapy, and with an increased use of therapy with a potential harmful effect. Widening the recruitment basis for this registry, as well as adjusting the use of the resources available and the reporting of data could increase the potential for REPORT-HF study to depict and explore the heterogeneity in the clinical epidemiology of heart failure worldwide. This approach would bring precious information that would fill the gap of knowledge where it is most needed. We declare no competing interests. Multimorbidity in patients with acute heart failure across world regions and country income levels (REPORT-HF): a prospective, multicentre, global cohort studyMultimorbidity is highly prevalent among patients with acute heart failure across world regions, especially in high-income countries, and is associated with higher mortality, less prescription of guideline-directed heart failure pharmacotherapy, and increased use of potentially harmful medications. Full-Text PDF Open Access